Publications and other reference materials referred to herein are numerically referenced in the following text and respectively grouped in the appended Bibliography which immediately precedes the claims.
In the common practice of chemotherapy prescription therapy the physician (oncologist) prescribes the type of medication the patient needs to take and the dosage per weight or body surface. When the medication is delivered intravenously, as in the majority of the cases, the patient is invited to come to a medical institute, usually a hospital, to receive the medication.
On the day of arrival, the patient's body indexes, e.g. weight and blood count, are measured. When ready, the prescription is sent to the hospital's pharmacy, together with the prescribed drug. With this information, together with the drug's instructions for use, the pharmacist will adjust the dosage in the prescription so that it matches the exact conditions of the patient on that particular day.
The prescription preparation process will usually involve using a syringe to draw a correct dose of concentrated drug from a drug vial and then injecting the drug into a final container, usually an IV bag, from which the drug will be delivered to the patient.
There are cases, in which the drug will come in a powder form in the vial and will need a primary dilution in the vial, before being used (this happens in about 20% to 50% of the cases).
There are 3 common intravenous delivery methods by which cytotoxic drugs are delivered to the patients: 1) Infusion (roughly 80% of all prescriptions)—in this method the drug is diluted into an IV-Bag (infusion bag) and the bag is delivered to the hospital ward. 2) IV-Push (about 20% of all prescriptions)—in this method a syringe is filled with the concentrated or diluted drug, and the drug is given by an intravenous shot directly from the syringe. 3) Infusion pumps comprising a cartridge into which the drug is diluted.
There are three factors that make chemo drugs, also known as antineoplastic drugs, unique among other drugs that are prepared in a hospital pharmacy:                1. Very low therapeutic index, which means a very narrow margin between an effective drug dosage and a harmful dosage.        2. Antineoplastic drugs are considered hazardous [1], [2] and therefore require extra and unique care when being handled, for the protection of the pharmacy and the hospital personnel.        3. The prescription dosage is customized to the conditions of the patient, on the day of delivery because: 1) the drug's low therapeutic index, which means that the dosage needs to be adjusted very carefully to the patients indexes on the day of delivery; 2) the shelf life of antineoplastic drugs, after being diluted, might be very short (sometimes as short as 30 minutes) meaning that prescriptions cannot be prepared in advanced; and 3) the cost of the drugs is very high, and the health institutions wish to avoid incidences in which a prescription was prepared for a patient that did not arrive at the hospital.        
These three factors make the preparation of antineoplastic drugs a delicate and resource consuming process in hospital pharmacies.
The preparation of an antineoplastic drug prescription is carried out in very unique and highly supervised conditions:                1. There will usually be at list 2 professionals in charge of handling the preparation of the prescription; one that is in charge of data handling who in almost all cases is a certified pharmacist and a second who does the actual prescription compounding and might be a pharmacist or certified pharmacy technician. The first person (the pharmacist) will usually act as the process supervisor.        2. In order to protect the person who does the compounding, on one hand, and the sterility of the drug, on the other hand, strict environment conditions are required in the preparation room [2].        3. In recent years, observations have shown that, in spite of the strict preparation conditions, the hospital personnel that handle the hazardous drugs get exposed to them, through different (and sometimes surprising) exposure routes, the use of Closed System Transfer Devices (CSTD) such as those developed and manufactured by Equashield®, is becoming common and expected to become compulsory for the preparation of these types of drugs.        
On one hand, the preparation of a chemotherapy prescription is very technical; pulling the correct dose from a vial, and transferring it to an IV bag (or any other container). On the other hand, three major difficulties are associated with the process:                1. Error control [3], [4], [5]:                    a. As stated above antineoplastic drugs have a very low therapeutic index, and any deviation from the correct dosage might either be non-effective, or highly dangerous.            b. Administering the wrong drug to a patient might put him in great danger.            c. When the patient is already waiting at the hospital, pressure of time under which the prescriptions are being prepared may make the pharmacy personnel prone to making mistakes.                        2. Personnel Protection: Even after all the protection measures are taken still leakage and drips often occur—either because of human errors or equipment malfunction. These leakages put the hospital personnel and the pharmacy personnel under the risk of exposure to the drugs.        3. Preparation Capacity: As can be understood from the stated above, the exact prescriptions remain unknown to the hospital pharmacy up until the physiological indexes of the patient are measured. However, as soon as these indexes are taken, there is pressure of time to prepare the prescription as soon as possible, since the patient is now waiting for his medication and occupying a bed in the oncology ward. Since most patients come during certain hours during the day, this pressure increases. The pressure, together with the need for extra safety measurements, increase the risk for human errors, which in turn might lead to prescription preparation errors as well as to drug exposure because of careless work.        
The combination of very technical and repeatable procedures, on one hand, and the need for high precision and caution, on the other hand, calls for the automatization of the process.
It is therefore a purpose of the present invention to provide an automated drug compounding system for the handling and preparation of hazardous and sterile drug prescriptions and specifically chemotherapy drugs.
It is another purpose of the present invention to provide an automated drug compounding system designed to be installed in the hospital pharmacy and be integrated with the data system handling the prescriptions at the hospital.
Further purposes and advantages of this invention will appear as the description proceeds.